The present invention relates to an oxidation hair dye composition for dyeing hair based on a combination of developer substance and coupler substance, which contains at least one 2,5-diaminobenzonitrile compound and also to new 2,5-diaminobenzonitrile compounds.
Oxidation hair dye compounds have achieved a predominant position in the field of hair dyeing. The colors of the dyed hair arise by reaction of certain developer substances with certain coupler substances in the presence of suitable oxidizing agents.
Particularly 2,5-diaminotoluene, 2,5-diaminophenylethyl alcohol, p-aminophenol and 1,4-diaminobenzene are used as developers substances. Resorcinol, 4-chlororesorcinol, 1-naphthol, 3-aminophenol and derivatives of m-phenylenediamine are used as the coupler substance.
Oxidation hair dye compounds used on human hair have many special requirements. They must be unobjectionable in regard to toxicological and dermatological properties and provided a dyed hair color of the desired color intensity. Furthermore a satisfactory light- , permanent wave- , acid and friction resistance is required of the hair colors obtained in the dyeing process. In every case the hair color of the dyed hair must remain stable for at least 4 to 6 weeks despite the action to of light, friction and chemical agents. Moreover a broad pallete of different color shades may be produced by an appropriate combination of suitable developer and coupler substances.
With the current hair dye compositions however it is not possible to fulfill all aspects of the above-mentioned requirements, particularly since problems exist for the developer substances.